Chemistry Exam Past Questions and Answers | JAMB, WAEC and NECO

Chemistry is the study of the substances that make up matter. It looks at their properties, how they react with each other, and how these reactions can create new substances.

• Question 2171:

  A substance that is used as a ripening agent for fruits is

  Options:
  A) ethene
  B) propane
  C) methane
  D) butane
  Show Answer
  The correct answer is A .
• Question 2172: Hydrogen is readily released when dilute hydrochloric acid reacts with Options:
  A) Cu
  B) Na
  C) Au
  D) Ag
  Show Answer
  The correct answer is B .
• Question 2173: Some properties of chemical substances are mentioned below... i. sour taste ii. slippery touch iii. yields alkaline gas with ammonium salt iv. has pH less than 7 v. turns phenolphthalein pink.Which of the above are NOT typical properties of alkalis? Options:
  A) i, iv and v
  B) iv and v
  C) i and iv
  D) ii and v
  E) ii, iii and iv
  Show Answer
  The correct answer is C .
• Question 2174: Which of the following will react further with oxygen to form higher oxide? Options:
  A) NO and H₂O
  B) CO and CO₂
  C) SO₂ and NO
  D) CO₂ and H₂O
  Show Answer
  The correct answer is C .
• Question 2175:

  Duralumin consists of aluminum, copper?

  Options:
  A) Zinc and Gold
  B) Lead and Manganese
  C) Nickel and Silver
  D) Manganese and Magnesium
  Show Answer
  The correct answer is D .
• Question 2176:

  A compound contains 31.91% potassium, 28.93% chlorine and the rest oxygen. What is the chemical formula of the compound?

  [K = 39, Cl = 35.5, O = 16]

  Options:
  A) KClO₄
  B) KClO
  C) KClO₂
  D) KClO₃
  Show Answer
  The correct answer is D .
• Question 2177: Which of the following raw materials would be required from the smelting of iron ore in a blast furnace? Options:
  A) CaCO ₃
  B) Zn(NO₃)₂
  C) CuSO₄
  D) AICI₃
  E) CaSO₄
  Show Answer
  The correct answer is A .
• Question 2178: Which of the following atoms represents deuterium? Options:
  A) No protons = 1, No of neutrons = 0, No of electrons = 0
  B) No protons = 1, No of neutrons = 0, No of electrons = 1
  C) No protons = 1, No of neutrons = 1, No of electrons = 1
  D) No protons = 1, No of neutrons = 2, No of electrons = 1
  Show Answer
  The correct answer is C .
• Question 2179:

  Which of the following best represent solid gas mixture?

  Options:
  A) milk
  B) kerosene
  C) soil
  D) smoke
  Show Answer
  The correct answer is D .
• Question 2180:

  CU₂S_(s) + O_2(g) → 2CU_(s) + SO_2(g)

  What is the change in the oxidation number of copper in the reaction above?

  Options:
  A) +1 to 0
  B) 0 to +2
  C) +2 to +1
  D) 0 to +1
  Show Answer
  The correct answer is A .